CyanogenMod (http://www.cyanogenmod.org/) is a derivative of Android without the closed-source software and various additions. CyanogenMod is entirely open-source and free. CyanogenMod is written in C, C++, and Java. This OS uses a rolling-release cycle. CyanogenMod can run Android apps and supports APK files. Also, the Google Play Store also works on this system. Some features that CyanogenMod has that Android lacks includes theme changer, FLAC support, OpenVPN, tethering, Privacy Guard, and more. Versions after 9 use the Trebuchet user interface. Previous versions used the Stock Android Launcher (3 and 4) and then ADWLauncher (5, 6, and 7). CyanogenMod does not support all mobile devices. Check the official CyanogenMod website to see if your device is supported. If so, then before installing CyanogenMod, backup important files and data. Once done, go to the settings menu on the Android system. Next, enable the ability to install from "Unknown Sources" (in the security settings). Afterwards, obtain the CyanogenMod installer app (http://get.cm). The downloaded file is called "OneClick.apk". Install this APK and answer any prompts that may be seen. If the mobile device is supported and the install completes successfully, then the user can enjoy CyanogenMod. Below are some of the advantages and disadvantages of CyanogenMod versus Android.